package model;

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * @author 兴趣使然黄小黄
 * @version 1.0
 * 用于连接数据库与关闭数据库连接的工具类
 */
@SuppressWarnings({"all"})
public class DBUtil {

    private static final String URL = "jdbc:mysql://127.0.0.1:3306/blog_system?characterEncoding=utf8&useSSL=false";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "";

    private static volatile DataSource dataSource = null;

    private static DataSource getDataSource(){
        if (dataSource == null){
            synchronized (DBUtil.class){
                if (dataSource == null){
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource)dataSource).setURL(URL);
                    ((MysqlDataSource)dataSource).setUser(USERNAME);
                    ((MysqlDataSource)dataSource).setPassword(PASSWORD);
                }
            }
        }
        return dataSource;
    }

    // 获取数据库连接
    public static Connection getConnection() throws SQLException {
        return getDataSource().getConnection();
    }

    // 关闭数据库连接资源
    public static void close(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet){
        if (resultSet != null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (preparedStatement != null){
            try {
                preparedStatement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}
